Method of making couplings



March 16, 1937. l M. E. MITCHE'iLI. AL 2,074,021 I METHOD OF MAKING COUPLINGS original Filed April 16'. 1934 INVENTORS A ORNEY.

20 the apparatus.

Patented Mar. 16, 1937 UNITED STATES PATENT oFFlcE Harold W.

Fowler, Oakland, Calif.;

said

Mitchell assignor to said Mortensen and said Fowler OriginalY application April 16, 1934, Serial No.v

720,760, now Patent No. 2,044,252, dated June Divided and this application February 2, 1935, Serial No. 4,712

2 Claims.

The invention relates to coupling members such as used to readily attach and detach sections or extensions of iiuid circuits as air pressure systems and more particularly to the means 5 `and method of construction of one of the coupling members. The present case is a divisional application of our copending application Serial Number 720,760, filed April 16, 1934 issued as Patent No. 2,044,252 on June 16, 1936 and the subject matter herein claimed is taken from the aforesaid application.

In our previous patent application Serial Number`720,760 we have disclosed and claimed a coupling of the character described which is con- 315 vstructed n a` manner concealing the means of detachment of the coupling sections whereby the surreptitious removal of any portion of the air .lineis made substantially impossible without detectionfthereof by the attendant in charge of The coupling utilizes a section having a certain inside construction necessaryto perfect this operation and it is an object of the ipresent invention to provide a means and method for making thisconstruction possible. The invention possesses other objects and features of advantage, some of which, with theforegoing, will beset forth in the following description of the preferred form ofthe invention which is illustrated inthe` drawing accompanying and formingypartof the specification. It is to be understood, however, that variations in the `showingmade by the said drawing and description maybe adopted within the scope of the invention as set forthin the claims.

I Referringto said drawing:

l* Figure l lisalongitudinal sectional view "of Va "coupling constructed in accordance with our in-` vfention with the separate sections thereof attached.

Figure 2 is a transverse sectional view of the coupling 4and is taken on the plane of line 2--2 of Figure 1. Y p Figure 3 is a side elevation shown partly in section cf a tool constructed in accordancewith v the present invention and shown operativelyassociated with .atool and coupling section supporting means. Figure llis a transverse sectional view of the `tool and is taken substantially on the plane of theline uIl I--Il of Figure `3. Figure 5 is a View similar to Figure 3 but showing Atheengagementfof the tool in the coupling section. 2

Figure 6is-an elevational view of a reamer adapted to complete the forming operation of"V the coupling section.

With reference to the drawing, the coupling II'ofour invention comprises detachable male land female sections I2 and I3 which are ar-` ,5

ing washer 22 which is mounted in the'bore 2i andarranged to engage about the end I4 `of the-A15 male member, the latter being preferably formed with a slight taper to alford a wedged engagement with the washer. The washer further serves with the members detached as a seat for a valve 23 which is mounted for axialmovement 20 inthe bore 2| and is normally urged by `a spring 24 'to seat against the washer in passage closing position and is displaceablefrorn such position only by and upon insertion of the male end I4 through the washer. Ashereshown the female, 25 section is comprised of two parts including a" main body casing 25' and a hollow Tendplug 26 therefor which defines the aforesaid engageable outer end I6 of the section "and 'which extends centrally into the 'casing V25 for 1clamping `the 30 washer 22 in positionagainst a retaining ring 21. Preferably formed integrally with themember 26 and extending into `the passage 2| in spaced relation to the washer 22 is an annular shoulder 29` which defines 'with the latter a 35 chamber forthe Valve .23 and affords inaddi' tion a support for the vouter end of the. valve spring 24.

Thus with the members detached the valve will be urged both by the iiuid flowand by the I spring 24 into passage closing -position against I the packing washer to prevent leakage `from the and female sections usually included a transverse pin or the like carried by the male section and which engaged in a bayonet slot in the female sectionrso that. on drawing the sections together and thentwisting one relative to the other ak 5 fastening of the sections was effected. In this type of connection the pin was of circular section and as a result could be forcefully twisted from a seated position in the slot. Also the pinas a rule extended through the bore in the male section and in this way not only obstructed fiuid ow but was a ready source of leakage should the pin become loosely held as a result)y of handling or rough usage. In accordance with the coupling of our invention, however, means of connection between the coupling member is so arranged as to entirely avoid possible disconnection of the sections or leakage in the manner aforesaid. In addition and as a particularly important and novel feature of the invention, the attachment means is arranged to completely conceal the manner of dissassembly of the coupling so as to render the latters disconnection by other than the method provided for practically impossible. This latter feature is carried out in the present invention by arranging the bayonet slot portion 3| of the connection entirely within the bore 2| at the end I6 of the female section and forming opposed slot engaging lugs or projections 32 on the interiltting end I4 of the male section, whereby with the sections attached both the slots and projections will be entirely concealed within the section I3. As here shown, the portion 3| consists of two diametrically opposed slots which extend from the open end of the bore 2| inwardly to an annular chamber 33. Thus upon insertion of the projections into the slots and effecting rst a relative axial movement of the sections until the projections are moved to the chamber 33 and then effecting a relative rotary twist of the sections, the projections will be moved into locked engagement behind the outer shoulder 31 of the chamber. Retention of the projections in this latter position is here arranged to be effected by forming in the shoulder at diametrically opposed points intermediate the slots 3|, a pair of sockets 38 arranged to receive and interlock with the projections. Since the insertion of the male section is resisted jointly by the spring 24 and the fluid iiow and as a result the resisting force will be applied in drawing the projections against the shoulder when the same are engaged as aforesaid, the movement of the projections into the sockets when aligned and a resultant locking of the parts will be insured. As an important feature of our invention and serving to prevent twisting of :the projections from the sockets, the latter are both formed of rectangular section so that no incline is available on the interengaged sides thereof for permitting a longitudinal disengaging movement incident to a forceful twisting of the projections and sockets. Thus with the members attached it is first necessary to move the sections toward each other to disengage the sockets and lugs and then rotate the sections to position the lugs opposite the slots 3| for ready withdrawal. When the coupling is attached as shown in Figures 1 and 2, the sections are so closely associated with each other as to disguise this initial longitudinal movement and as will be clear no other manipulation of the coupling sections such as twisting or pulling will be productive of their disassociation.

In previous couplings with which we are familiar it has been the practice of providing bayonet guide portions such as the grooves 3| here shown by cutting longitudinal slots through the female section which slots extend completely through and to the outside of the section side walls, and to provide the offset for locking portions of the slot by simply cutting sidewise from the inner end of the slot or by drilling the section at a portion contiguous with the inner ends of the slots. Since the operations entailed in forming these previous constructions are well known and commonly used in machine shop practice, the manufacture of the female section of the coupling presented no particular diiculty. In the present coupling however, wherein the guide portions 3| and the sockets 38 are formed entirely within the bore 2| of the casing 25 and are completely inaccessible for forming by the usual apparatus found in machine shops, the manufacture of the female section of the coupling requires the use of both a special apparatus and a new process of formation. In the case of the female section 25 as here disclosed, the same may be initially prepared prior to the formation of the grooves and sockets 3| and 38 by first drilling axially through the member from the outer end 50 thereof with a drill diameter slightly larger than the male end I4, then reaming from the same end to define the shoulder 3l and a seat 5I and then tapping the reamed bore adjacent the end I8 to form internal threads for the hollow plug member 26. Our new process of forming the aforesaid grooves and sockets consists briefly in punching from the reduced bore portion of the section between the shoulder 31 and the end I6 the grooves 3| while supporting the inner wall of the bore, and then depressingv the sockets 38 while supporting both the side walls of the bore and the walls of the grooves 3|. Preferably following the punching operation, the

end I6 of the section is counterdrilled, and

reamed, as indicated in Figure 6 in order to remove any bur or swelling incurred by the punching.

The punching of the grooves and sockets as well as the supporting of the bore side walls and grooves during the punching operation is ar-V ranged to be effected by a special tool 53. With reference to Figures 3, 4 and 5 the tool comprises a cylindrical body portion 56 which is arranged to slidably engage in the bore of the female section and support the side walls thereof during the punching operation and is provided on opposite sides thereof with a pair of offset rectangular projections 54 which are arranged on the forceful movement of the tool through the bore to engage the shoulder 31 and shear from the reduced bore portion the grooves 3|. Provided also on the periphery of the body portion 53 of the tool and at substantially right angles to the projections 54 is a second pair of offset rectangular projections 55 which serve to engage the shoulder 3'."`

and depress the sockets 38 therein after the grooves 3| have been sheared from the side walls of the bore. To effect forming of the sockets only after the formation of the grooves has been completed or substantially so, the projections 55 are spaced longitudinally from the projections 54 so that their operation will be retarded from that of the projections 54. It is important during the pressing of the recesses 38 and the tremen dous strain to which the metal of the coupling is thereby subjected, that the side walls of the grooves 3| be held against partial closing or other distortion. For this purpose the projections 54 are extended longitudinally along the body portion of the tool a distance substantially equal to the length of 'the grooves 3| so that after the forming of these grooves the projections 54 will lie snugly therein and hold the side walls thereof against any possible distortion due to stress on the metal incurred by the pressing out of the sockets 38. After the pressing operation the bore of the section at the grooves 3l is preferably rounded and the end I6 ared by means of a reamer 59 as indicated in Figure 6, to remove any bur or distortion caused by the punching out of the grooves and sockets.

As indicated in Figures 3 and 5 an end 6I of the tool may be mounted in an ordinary punch press B2 and the coupling section 25 positioned on the work support 63 thereof Within a guard 64 for holding the section against Withdrawal With the tool.

We claim:

1. In a method of forming a tubular coupling section having a portion of the bore thereof reduced adjacent an end thereof to define a shoulder spaced from said end, and forming a longitudinal guide groove in the wall of said bore from said shoulder to said end which comprisesthe following steps, supporting the wall of said reduced bore portion against distortion and forcing a tool longitudinally through said bore While so supported for punching out said groove, by

a portion of said tool and subsequently forming a locking recess in said shoulder by another portion of said tool.

2. In a method of forming a coupling section provided with a bore therethrough and having a portin of said bore reduced adjacent an end thereof to dene a shoulder in said bore spaced from said end, and forming longitudinal guide grooves in the Wall of said bore from said shoulder to said end and of forming locking recesses in said shoulder which comprises the following steps, supporting the Wall of said reduced bore portion against distortion and forcing a tool longitudinally through said bore 'while so supported for punching out said grooves, and then while supporting said bore wall as aforesaid supporting .said grooves against distortion and forcefully engaging a tool with said shoulder to depress longitudinally therein said recesses.

MALCOLM E. MITCHELL. PETER E. MORTENSEN. HAROLD W. FOWLER. 

